LOS ANGELES , California -LRB- CNN -RRB- -- Singer Chris Brown pleaded not guilty to both charges in the felony assault case against him Monday afternoon .

Singer Chris Brown , right , appeared in court Monday on charges of assaulting singer Rihanna .

Singer Rihanna , the girlfriend Brown is accused of attacking , wants the case resolved without a trial , her lawyer said .

The only words heard from Brown , 19 , during his brief appearance before Judge Patricia Schnegg were `` not guilty , '' which he said twice as Schnegg asked for his plea on the two counts .

Brown is charged with felony counts of assault and making criminal threats . If he is convicted , the sentence could range from probation to four years and eight months in prison , the Los Angeles County District Attorney 's Office has said .

The alleged attacked happened during an argument in February that began when 21-year-old Rihanna , who had been dating Brown , found a text message from another woman on his cell phone , according to a sworn police statement . Watch Chris Brown enter his plea ''

Rihanna 's lawyer , Donald Etra , told reporters after Monday 's hearing that his client `` would prefer that the matter be resolved expeditiously and fairly . ''

`` She believes that the quicker this case is over , the more quickly she can get back to her life and her career , which is exactly what she 'd like to do , '' Etra said .

Rihanna , who is in her home country , Barbados , `` is in fine spirits , she 's doing fine , '' he said .

`` She would be pleased if this were over quickly , '' Etra said .

He said there were `` efforts on behalf of all of the parties to try to resolve the case expeditiously and fairly . ''

The goal is `` to see if it can be resolved prior to the preliminary hearing and prior to trial , '' Etra said . `` I think that would benefit everybody . ''

When asked if Rihanna would cooperate with prosecutors , Etra gave the same response he 's given previously .

`` If asked to testify , she will do so , '' he said .

He said it was `` premature to speculate '' what Rihanna might consider a fair plea deal for Brown .

When Brown appeared for his first hearing a month ago , Rihanna 's lawyer asked the judge not to prohibit Brown from having contact with her while he faces felony charges of assaulting her . Watch Brown at his March court appearance ''

The judge granted Rihanna 's request , only warning Brown `` not to annoy , harass , molest , threaten or use force or violence against anyone . ''

Court documents released last month revealed details about the case against Brown , including a police statement that the incident began when Rihanna , whose full name is Robyn Rihanna Fenty , found a text message on Brown 's cell phone from `` a woman who Brown had a previous sexual relationship with . ''

Brown issued a public apology for the incident in February .

`` Words can not begin to express how sorry and saddened I am over what transpired , '' he said in a statement released by his spokesman . `` I am seeking the counseling of my pastor , my mother and other loved ones and I am committed , with God 's help , to emerging a better person . ''

Brown has not commented publicly since issuing that statement .

The next court hearing in the case is set for April 29 .

CNN 's K.J. Matthews and Denise Quan contributed to this report .

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NEW : Chris Brown 's girlfriend , singer Rihanna , does n't want a trial , lawyer says

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Brown arraigned Monday afternoon in Los Angeles , California

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Brown accused of assaulting Rihanna in February

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Police say Brown and Rihanna had argument that became violent